The ability to store processed and unprocessed photographic film without change in the properties of the film is important to maintaining exposed and developed films, as well as maintaining consistent performance of unexposed films. The archival keeping properties of photographic films are expected to be measured in decades. The properties of unexposed films are intended to remain stable over many months of storage in various conditions.
It is common practice to use hermetically sealed containers of plastic or metal, or to seal in metal coated polymer bags to prevent moisture access to films. It is also desirable to protect films from gases such as SO.sub.2 and ozone. Other materials such as food also need sealed and protective packaging. This is commonly referred to as Modified Atmosphere Packaging (MAP). This is where you create a specific ambient condition within a package different than typical ambient atmospheric condition.
Further, it has been disclosed in U.S. Pat. No. 5,215,192--Ram et al that particulate materials such as molecular sieve zeolites may be placed in film storage containers for exposed films to improve their storage properties. Desiccants also have been proposed for package insert or coating material for a package for film or cameras in U.S. Pat. No. 4,036,360--Deffeyes.
It has been proposed in U.S. Pat. No. 5,189,581--Schroder that desiccants be placed within video cameras in order to dry the cameras.
U.S. Pat. No. 5,789,044--Ram et al discloses the use of zeolite molecular materials to form a part of a structure that is utilized for storing or holding film.
It is disclosed in U.S. Pat. No. 5,633,054--Hollinger, Jr., U.S. Pat. No. 5,525,296--Hollinger, Jr., and U.S. Pat. No. 5,683,662--Hollinger, Jr. that materials such as hydrophobic molecular sieve materials may be incorporated into fiber materials. The molecular sieve materials are crystalline, hydrated metal aluminosilicates which are either made synthetically or naturally occurring minerals. Such materials are described in U.S. Pat. Nos. 2,882,243; 2882,244; 3,078,636; 3,140,235; and 4,094,652.
In packaging of unexposed photothermographic films, there has been found to be particular difficulty in that present packaging methods for such films utilized in the health care business do not result in good storage properties even though sealed in plastic film bags having a metalized layer. There is a need for improved packaging materials for such films.
However, the above systems for placing desiccants into a package suffers of from disadvantages. The desiccant packs may be difficult to dispose of. Further, the packs contain polymers which are expensive and may inhibit absorption gases to the zeolite or other humiditants. Further, they cause an inconvenience and expense in packaging in that a separate item must be added to the package, and such external elements may induce pressure sensitization of films.